Im exactly like you and I have no COMT mutations. I dont doubt at all it is influencing your anxiety and making things worse by doing what anxiety does, but I dont think at all that it is the sole cause of those problems. I do think addressing it could help those problems, as well as addressing other things like GABA glutamate balance and getting inflammation down. You are getting the picture, all those things are interwoven and the state of any one of those things will influence all others. I always tell people to do what they can to get the pendulum swinging in the right direction.
Inflammation plays a far greater role in digestive problems like that than anxiety does. But anxiety fuels inflammation.
There are things you can do to upregulate COMT. I dont remember any of them off the top of my head, I’ll look it up when I get a few minutes.